Telegraph repeater



J. HERMAN TELEGRAPH REPEATER Filed May 2l, 1924 I N VENTOR He/0mm ATTORNEY i 5 0 larity..

Patented Dec. 13, 1927. l y f UNITED STA TES PATENT OFFICE.

JOSEPH HERMAN,'OF NEW YORK, N. Y., ASSIGNOR TO AMERICAN TELEPHONE AND Y TELEGRAPH COMPANY, .A CORPORATION OF NEW YORK.

TELEGRAPH REPEATER.

Application filed ,May v21,

This invention relates to improvements 'in metallic telegraph circuits and 4more particularly ,to improvements in the repeater sets utilized 'in such systems.

It is often .desirable in telegraph systems for an operator to interrupt another opera. tor sending at a distant station and thus get control of' the line. This operation is known as breaking. One ot the objects of this invention is to provideimproved forms. o't

breaking arrangements. In accomplishing this in the arrangements of the invention, the -two Wires of the metallic circuit are utilized to Jform two oneway telegraph .channels during the transmission ot the break signal. -Another vfeature 'ot the invention consists in providing vibrating` circuit windingsfor the various line relays so as to cause these relays to vibrate should the line be momentarily opened. This operates to prevent the locking up ot the system due to accidental operation of the break relays. Anotherteature ot' the Ainvention consists in the fact that with these arrangements no artiiicial line is needed and the usualV adjustments for line balance may be obviated Other features and objects of the invention will appear more fully from the detailed description hereinafter given.

The invention may be incre fully underlstood' from .the following` description, to- Age.ther wi.th the .accompanying drawing, in

the figure .of which the yinvention is illustrated.

85 lIn 4the figure are shown two stations at ywhich are located terminal telegraph repeaters interconnected by Vthe metallic circuit L. The repeater set at station 1 comprises a ,loop .circuit 1 including` a key K, a battery, a 49 subscribers loop, and windings of a transmitting relay yA .and a break relay B. The transmittingv relay A controls its armature A, which has marking and spacing contacts whereby impulses of opposite polarity may .4.6 be applied Vto the tip conductor of line L. The break relay B controls its armatureB1 which co-.operates with marking and spacing `contacts which are normally connected by conductors vand 6 to sources of opposite po- .A receiving relay D is provided ,has a plurality of windings. The

Which winding N is serially includedfin the ring side .of the lineand the vwinding M yis adapted arto be connected across the line conductors.

Afbattery 2-and a suitable resistance arelcon- 1924. serial Np.. 714,934.

f shown which Vcontrols the armatures El and E, and their associated contacts. Atransfer relay C is also provided. This relay controls the .armatures C`.C2 and C3 and' their` associated contacts. The apparatus at station 2 is substantially similar to that at station 1 eXcept'that the armature of the transmitting relay is connected to the ring side of'V the line. Similar reference characters withthe added designation prime have been utilized to denote like parts at both stations.

The arrangements of the invention operate in the following manner. Assume that st-ation 1 isr sending. In this case the arma-turc Y Al of the transmittting relay A is connected to the tip side ot' line L. Signals Jfrom the transmitting relay A at station 1 will be sent out .to .station Q along the tip conductor.y At station 2 the windings'M and N of the receiving` relay D are connected directly across the two line wires as shown and the relay will vvbe operated by the incoming signals. A battery 2 in series with a suitable resistance is connectedto the midpoint ot these windings of the receiving relay D and causes a `longitudinal current to low along the two line wires to station 1. This current Hows through Athe winding N of the receiving relay D to ground and is .of such .a nature that it will hold said relay on lits mark-v ing contact, thereby permitting the opera'- tor in the local loop circuit 1 to continue to send. Under these conditions the auxiliary relay E and the transfer relay C at station 1 are both deenergized. Relay C is open circuited at the contacts associated `with armatures E2 ,and 'C3 and relay Ehas the same Ybattery polarity connected to 'both ends of its winding as long as the armature D, of the receiving relay remains on its marking contact.

It VtheV operator at station 2 wishes to interrupt or break the operator at station 1, he 4opens his "key K" which causes the followingsequence of operations to take place. Relays A and B cause their armatures A1 and B', This operation 'of armature B 1 will connect negative or marking battery to both ends of the winding of relay -C and cause it to become deenergized. The deenergization of relay C disconnects the battery .2 at the middle of the windings ot relay D from the line and connects spacing battery from the armature A', to the ring conductor of the line. This spacing battery is ot an opposite potential to the potential applied to the ring conductor by bat-tery 2 and hence will ilow through winding N of relay D at sta'- tion 1 and cause relay D to operate its armature D,L to its spacing contact. This will interrupt the operator at station l for it causes positive or spacing battery to be ap plied vto both ends of the loop circuit upon the closure ot' key K. The operation ot armature Dl to its spacing V'contact will close the following circuit: from marking battery, conductors 5 and 7, armature C3 and its lefthand Contact, winding oi relay E, armature Dl, conductors 8 and 9, armature B1, conductors 10 and 6, to spacing battery. This will operate relay E which will cause the armature El to move to its spacing contact and thus put spacing battery on both contacts of the receiving relay and will cause the armature E, to close its Contact. This latter operation will close the following circuit: 'from' marking battery, conductors 5 and 7, Contact and armature E2, winding of relay C, conductors il and 9, armature B1, conductors 10 and 6 to spacing battery. This will operate the relay C which will operate its armature C, toclosea locking circuit for itself and to open the previously traced circuit for relay E. This will deenergize relay E which will release its armature E, and restore the batteries on the receiving relay contacts to normal. Upon the opera-tion of relay C the armatures C, and vC2 will operate and disconnect the transmitting branch of the repeater set from the line and connect the windings M andN of the receiving relay D across the line conductors. The holding battery 2 connected to the midpoint of these windings will cause a current to ytlow over the tip conductor and through the winding N to ground at station 2. This current will be such thatV it will cause the armature Dl of the receiving relay D and station 2 to remain on its marking contact.

It the interrupted operator at station l keeps his key K closed, the operator atstation 2 can begin to send t'or relay C will remain operated as long as the armature B1 of the break relay remains on its marking contact. Should the operator at station l now open his key, the break relay will cause its armature B, to move to spacing and cause relay C to release. This will transmit a break signal back to the operator at station 2 in a similar manner to that alreadydescribed.

It is pointed out that the vibrating circuits 25 and 25 of a. well-known type are connected to the receiving relays D and D of both sets. This arrangement prevents the locking up of the system due to the accidental operation of a break relay.V Such operation, which may be due to accidental opening of the line at the switchboard or the introduction of foreign `currents upon the line wires, connects a receiving relay winding across each end of the line. Under this condition the line. current is zero and the circuit would be locked up it both receiving relays should happen to remain on spacing. This latter condition is prevented by the provision of the vibratingcircuits which, under 'such conditions, wouldcause both receiving relays to vibrate until the key is opened at either end of the line, afterv which the circuit is again in normal operate ing condition. The same condition may occur when the line is opened. In that case, however, the relays will continue to vibrat until the circuit is restored.

lVhile the invention has been disclosed in certain specitic arrangements which are deemed desirable, it is understood that it is capable oi embodiment. in many other widely varied forms without departing from the spirit and scope ot the invention as defined in the appended claims.

What is claimed is: y

l. A metallic telegraph circuit` interconnecting two stations, repeater sets at each of said stations, receiving relays at each of said sets, each ot' said relays having two windings, the relay at one station having a wind# ing adapted to be connected 'across said telegraph circuit and another winding adapted to be included serially in the ring con- M ductor of the circuit, the relay at the other station having` a winding adapted to be con nected across said telegraph circuit and an# other winding adapted to be includedfserially in the tip conductor of the circuit, means cont-rolled from one station over the tip con-V ductor of the circuit for controlling the' association with the circuit of the relay windings at the distant station therefrom, and means controlled from the other station over the ring conductor of the circuit for controlling the association with the circuit of the relay windings at the distant stationtherefrom.

2. A metallic telegraph circuit comprising tip and ring conductors for interconnecting twost-ations, repeater sets at each of said stations, each of said repeater sets'including y transmitting and receiving apparatus, means at each of said repeater sets for controlling the association of said transmitting and receiving apparatus with said telegraphcir cuit, and means ior controlling one of said last mentioned means from a distant station over the tip conductor or" the circuit and for controlling the other of said last mentioned means from the other station over the ring conductor of said circuit. f 5

3. A metallic telegraph circuit comprising tip and ring conductors vfor interconnecting two stations, repeater sets at each of said sta- 5 iso if tor and through means at one of said sets for transmitting a break signal to the other set over the tip conductor of said circuit, and means at the other set for transmitting a break sig nal to said first mentioned set over the ring conductor of said circuit.

4. A metallic telegraph circuit interconnecting two stations, a receiving relay at one station having two windings, said'receiving relay beingso associated ywith the circuit that when signals are being transmittel fromv said station one of said windings will be disconnected from said circuit and the other winding will be included seri-ally in one of the line conductors, means at the other station for transmitting a signal over said line conductor and through said last mentioned winding to operate said relay, an auxiliary relay controlled by lay, a transfer relay controlled by the operation of said auxiliary relay, and means controlled by said transfer relay for connecting both of said receiving relay windings across said telegraph circuit.

5. A metallic telegraph circuit interconnecting two stations, a receiving relay at one station having two windi-ngs, said receiving tions,

relay being so associated with the circui-t that` when signals are being transmitted from said station one of said windings will be disconnected from said circult and the other winding'will be included serially in one of the line conductors, means at the other station for transmitting a signal over said line conducsaid last mentioned winding to operate said relay, an auxiliary relay controlled by the operation of said receiving re` lay, a transfer relay for connecting both of vconnected across said circuit with the the operation of said receiving renecting two stations, receiving relays at each of said stations, said relays each having two windings,

being included serially in different ones of the line conductors of said circuit and the second winding of each relay being adapted to be disconnected from said circuit or to be winding, and holding batteries connected to the midpoint of the windings of each relay, and operating through the windings of the relay at the distant station to maintain said relay in a predetermined povsition.

7. A metallic telegraph Vcircuit interconnecting two stations, receiving relays at each Y said relays each having two of said stations,

of each relay windings, the first winding the first winding of each relayA first first mentioned being included serially in different ones of the line conductors of said circuit and the second winding of each relay being adapted tobe disconnected from said circuit or to be connected across saidy circuit with the first winding, holding batteries connected to the midpoint of the windings oiV each relay and operating throughthe lirstmentioned windings of the relay at the distant station to maintain said relayV in a predetermined posi and vibrating ci-rcuit'windings ass'ociat-V tion, ed with each of said receiving relays.`

In testimony whereof, I have signed my name to this specification this 19th day of May, 1924. Y

JOSEPH HERMAN. 

